1. Field of the Invention
This invention relates to an improved cooking and heating apparatus for food. More particularly, this invention relates to an improved food cooking and heating apparatus which maintains heated food temperature without rapid deterioration of food quality by regulation of the amount of air flow through the apparatus.
2. Description of the Prior Art
Food cooking and heating cabinets are well-known devices used to cook food slowly and used to maintain heated food at serving temperature. Cooking and holding cabinets have become valuable tools in the food industry, particularly in fast food and institutional applications. They allow food to be cooked in advance and then held at the desired serving temperature. The cabinet must be large enough to hold many servings, yet maintain a uniform temperature throughout. The food texture, moisture, color, and flavor must be maintained during the time period the food is held in the cabinet. The most important quality to be maintained is food moisture.
Early cooking and heating cabinets utilized radiant heating of the oven. A heated outer jacket transfered heat through the oven walls to heat the food therein. The next advance in the art was seen where the heated jacket was closed and the air therein recirculated. These approaches suffer two major drawbacks. First, it has been impossible to achieve uniform heat in the larger cabinets presently in use. Second, an unduly long period of time is required to recover the desired temperature after the oven door is opened.
For this reason, it has been found advantageous to circulate heated air through the oven and around the food. In practice, ovens were modified to provide openings in the oven walls to allow a small portion of heated air to circulate through the oven. In one embodiment, all of the heated air is circulated through the oven and returned to the heating chamber with the use of a blower. A heating element, used to heat the air in a heating chamber, is controlled by a thermostat and a heat sensitive switch. When the air reaches a desired temperature, the heating element is switched off. Uniform heat and quick temperature recovery may be achieved; food quality, however, is decreased due to drying caused by the heated air passing over and around the food.
In another approach to avoid the drying effect, heated air is circulated in a food chamber in a circular pattern around the food which is centered at the “eye of the tornado”, where air circulation is minimized.
Other attempts to address the problem of deteriorating food quality include adding moisture back into the air. A water pan is positioned so that the heated air flows over the surface of the water. There are two problems that arise. It is believed that decreasing the drying effect and retaining the natural moisture of food is superior to adding moisture to the atmosphere. Additionally, the water pan requires constant refilling, which is time consuming and is often overlooked by restaurant and institutional attendants.
Therefore, it is a principal object and purpose of the present invention to maximize food quality in a food cooking and heating apparatus by controlling the amount of air and the temperature of the air passing over and around the food.